Created attachment 632640[details]
Fiddler2 Screenshot showing multiple requests
I visited http://www.crazy-factory.com/product_listing_ng.php?cat_id=316 and noticed that the product images load very slow.
After investigating with Firebug and Fiddler2 I noticed that the product images inserted by JavaScript are requested multiple times, blocking each other. As soon as they are locally cached the problem doesn't occur anymore.
This only happens in Firefox 14 and above, Firefox 13 shows no problems. This was tested in a clean Windows XP VM with clean profiles. Versions:
Firefox Stable 13.0 (working as expected)
Firefox Beta 14.0
Aurora 15.0a2 (2012-06-12)
It does not happen in IE9 and Chrome 21.
Sadly I was not able to create a reduced test case - all reduced test cases that I ran locally didn't have that problem and requested the images just fine from the original server.
If needed, all minified JavaScript files are also available uncompressed on the server, just remove ".min" from the URL.

Created attachment 638761[details][diff][review]
fix
We call ContinueConnect() in OnCacheEntryAvailableInternal() even if the channel was canceled. This patch is a quick fix for this issue. I still need to check all other failures in OnNormalCacheEntryAvailable(), OnOfflineCacheEntryAvailable() and OnOfflineCacheEntryForWritingAvailable() whether we correctly cancel the request or continue without the entry...